“Taking Woodstock” motors along at its own gentle pace only to stumble when the festival itself heats up. Then everything about the movie falters: Demetri Martin’s performance slips, just as his character Elliot starts to come out of his shell, and you’re reminded, yes, this is “The Daily Show” guy.

The scenes of the festival itself are the most disappointing: Ang Lee just doesn’t seem like the right guy for the job. Think about it: Would he be the director you’d think of to film an acid trip? He’s very good at clenched suburbanites experimenting with key parties in “The Ice Storm,” not so much a first acid trip.

In truth, few directors film hallucinogenic scenes well. That’s but one reason why AMC’s “Breaking Bad” is so good: Vince Gilligan manages to film trippy scenes in an interesting way. You need not have ever partaken of the substances in question to appreciate them.

When the movie segues back from the fest to the intra-family drama, it’s affecting again. Henry Goodman, who plays Elliot’s father, will break your heart.